Here's one to get started with. It's kind of a mix match of 555 timer projects: Semaphore and 555 Timer Circuit
It goes back a few years, covers some different things done with 555 timers and CD4017 counters and ends up with a 4 way traffic light signal board. (It's also where this thread originated.) I'll re-read it all and try to give a better description of all that is covered.